Berkshire: Newbury Aliens

5 September 2013

1-2 hours

If in Newbury with a couple of hours to spare in September it is worth seeking out the wasteland flowers.

          We started at the most productive site, the station car-park, handy whether arriving by train or car.  We immediately spotted Oxford ragwort Senecio squalidus [South Europe] with its lax umbels of flowers larger than common ragwort, along with redleg Persicaria maculosa, annual mercury Mercurialis annua, weld Reseda luteola and thyme-leaved sandwort Arenaria serpyllifolia, right next to the station platform. 

Oxford ragwort

Beside these was a single clump of rough bristle-grass Setaria verticillata [also from warmer climes to the east].

Rough bristle-grass

Immediately then came the first of many Bilbao's fleabanes Conyza floribunda [South America].  Similar to Canadian fleabane, the latter has red-streaked roughly hairy stems (the quickest field character) and (with a good lens) 5-lobed disc-flowers (4 in C. canadensis).  While Canadian fleabane was at one time the commonest of these Conyza species, here at least Bilbao's has become dominant, to the extent that we could not find any canadensis here at all, nor in other parts of central Newbury.  Bilbao's fleabane was first recorded in this car-park in 2001 (Crawley's Flora of Berkshire) and has thus become thoroughly naturalised.

Bilbao's fleabane

A bank across the car-park had fennel Foeniculum vulgare [Europe], wild carrot Daucus carota, hemp-agrimony Eupatoria cannabinum, Canadian goldenrod Solidago canadensis [North America], and purple toadflax Linaria purpurea [Italy].  Looking for Conyza species a specimen with red phyllaries (outer bracts around the flowers) seemed at first to be Argentinian fleabane, but we eventually realised that it was more like the commoner blue fleabane Erigeron acer, the two genera being very close.  It had red stems, while those of Argentinian fleabane seem to remain green, while only the tips of the bracts are red.  A close look revealed pale purple outer ligules to the flowers, but these were much more reduced than normal in blue fleabane and the plant was more branched and bushy.  We wondered whether it was a hybrid between blue fleabane and a Conyza species.  A hybrid between blue fleabane and Canadian fleabane has occasionally been found and is named X Conyzigeron huelsenii.  It usually has some abortive capsules, while our specimen seemed fully fertile, which would not be expected for a hybrid.  The photographs compare our possible hybrid with a true blue fleabane photographed at Beedon, just north of Newbury, where it was abundant in one field.  [We have received a comment from Artur Pliszko in Poland saying that this specimen is ssp serotinus of Erigeron acer, which is different from the type species (heads in a raceme rather than a panicle, leaves undulate and down-turned, red stems), but the distributions of ssp serotinus and ssp acer do not seem to have been studied in Britain.  We have accordingly re-labelled the following pictures - 20 March 2015.]

Erigeron acer ssp serotinus

Blue fleabane ssp acer

This bank by the car-park and others on the far north side were dominated by a strange tall white-woolly mullein with large yellow flowers.  This was Broussa mullein Verbascum bombyciferum [Turkey], first recorded at this very site in 2004 (Crawley's Flora of Berkshire).  Apart from its odd appearance, the species has narrow spathulate stigmas and the anthers on the two "lower" stamens running down on to the stamen rather than being sat crosswise on top like the other three.  (Stace uses "lower" but this refers to the position in the flower and not to their length, as these two stamens tend to be taller than the others - very confusing!)

Broussa mullein

In the NE corner of the car-park was a patch of variegated Algerian ivy Hedera algeriensis [North Africa], leaves mostly unlobed with red stalks, not recorded in the Berks Flora.

Algerian ivy

The warm micro-climate of the car-park, apart from favouring these plants from warmer climates, was also popular with field grasshoppers Chorthippus brunneus.

Field grasshopper among young plants of Broussa mullein

Leaving at the west end of the car-park we crossed into Bartholomew Street, going north through a main shopping area to St Nicholas's Church.  The churchyard had harebell Campanula rotundifolia in less frequently cut grass areas on the north side, with pellitory-by-the-wall Parietaria judaica.  A cultivated strip by the walls of the church on the east side had lesser meadow-rue Thalictrum minus and "Japanese" lantern Physalis alkekengi [Europe] with its bright orange seed-cases.  The latter is recorded in Crawley's Flora of Berkshire as abundant here in 2001, but there were now just a few plants.  The same source only gives the meadow-rue for a rubbish-tip in Newbury in 1961, so this is a new addition to the churchyard.  Autumn crocus Crocus nudiflorus is recorded here but we were too early to see any, even if it does survive.

Japanese lantern

We then crossed the market-square to the east and wended our way through other car-parks back to the station.  The only fleabane we saw other than Bilbao's was one very large clump of Guernsey fleabane Conyza sumatrensis [South America] beside one wall, growing with buddleia Buddleja davidii.  Apart from being tall and bushy this fleabane is conspicuously hairy.  This made it a three-fleabane day, four if one counts the possible hybrid.  It also completed our tour of the world inside one square kilometre.

Guernsey fleabane